Remove memory ordering from LeftRight (#31026)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/31026
This is error prone and probably wrong. Since we don't use LeftRight on the hot path anymore, let's remove this.
ghstack-source-id: 96369644
Test Plan: none
Differential Revision: D18902165
fbshipit-source-id: 7b9478cd7cc071f403d75da20c7c889c27248b5c
